In large aperture optical systems such as astronomical telescopes, wavefront distortion is a serious problem which places limits on the angular resolution which can be achieved. The wavefront distortion can occur from deformation of the mirror elements due to mechanical and thermal stresses and/or deformation of the incident wavefront caused by turbulence in the atmosphere. Indeed, because of the latter effect, no large ground-based astronomical telescope presently in existence can achieve anywhere near diffraction-limited performance. One approach to overcome such distortions is to use adaptive optics: that is, a multiplicity of electromechanical actuators are positioned on the primary or secondary mirror to locally reposition the surface of the mirror to correct for wavefront distortion due to mirror deformation or atmospheric turbulence. However, this is a complex and expensive solution. For example, a forty-eight inch diameter mirror having local adjustable regions three inches on a side would require approximately 200 actuators, with all the attendant electronics and controls. Three inches is about the size of the typical atmospheric disturbance cell. While this approach often makes economic sense for very large systems where a segmented structure comprising many small mirror segments each independently adjustable is less expensive than one large monolithic mirror, it is not so with respect to smaller systems. Yet smaller systems, while not so susceptible to mechanical and thermally induced wavefront distortion, nevertheless suffer from wavefront distortion due to atmospheric perturbations that deform the incident wavefront and limit the resolution of ground-based systems.